crop a stars object
crop a stars object
## S3 method for class 'stars_proxy' st_crop( x, y, ..., crop = TRUE, epsilon = sqrt(.Machine$double.eps), collect = TRUE ) ## S3 method for class 'stars' st_crop( x, y, ..., crop = TRUE, epsilon = sqrt(.Machine$double.eps), as_points = all(st_dimension(y) == 2, na.rm = TRUE) )
x |
object of class |
y |
object of class |
... |
ignored |
crop |
logical; if |
epsilon |
numeric; factor to shrink the bounding box of |
collect |
logical; if |
as_points |
logical; only relevant if |
for raster x, st_crop selects cells that intersect with y.
For intersection, are raster cells interpreted as points or as small polygons?
If y is of class stars, x raster cells are interpreted as points; if y is of class bbox, x cells are interpreted as cells (small polygons). Otherwise, if as_points is not given, cells are interpreted as points if y has a two-dimensional geometry.
l7 = read_stars(system.file("tif/L7_ETMs.tif", package = "stars"))
d = st_dimensions(l7)
# area around cells 3:10 (x) and 4:11 (y):
offset = c(d[["x"]]$offset, d[["y"]]$offset)
res = c(d[["x"]]$delta, d[["y"]]$delta)
bb = st_bbox(c(xmin = offset[1] + 2 * res[1],
ymin = offset[2] + 11 * res[2],
xmax = offset[1] + 10 * res[1],
ymax = offset[2] + 3 * res[2]), crs = st_crs(l7))
l7[bb]
plot(l7[,1:13,1:13,1], reset = FALSE)
image(l7[bb,,,1], add = TRUE, col = sf.colors())
plot(st_as_sfc(bb), add = TRUE, border = 'green', lwd = 2)
# slightly smaller bbox:
bb = st_bbox(c(xmin = offset[1] + 2.1 * res[1],
ymin = offset[2] + 10.9 * res[2],
xmax = offset[1] + 9.9 * res[1],
ymax = offset[2] + 3.1 * res[2]), crs = st_crs(l7))
l7[bb]
plot(l7[,1:13,1:13,1], reset = FALSE)
image(l7[bb,,,1], add = TRUE, col = sf.colors())
plot(st_as_sfc(bb), add = TRUE, border = 'green', lwd = 2)
# slightly larger bbox:
bb = st_bbox(c(xmin = offset[1] + 1.9 * res[1],
ymin = offset[2] + 11.1 * res[2],
xmax = offset[1] + 10.1 * res[1],
ymax = offset[2] + 2.9 * res[2]), crs = st_crs(l7))
l7[bb]
plot(l7[,1:13,1:13,1], reset = FALSE)
image(l7[bb,,,1], add = TRUE, col = sf.colors())
plot(st_as_sfc(bb), add = TRUE, border = 'green', lwd = 2)
# half a cell size larger bbox:
bb = st_bbox(c(xmin = offset[1] + 1.49 * res[1],
ymin = offset[2] + 11.51 * res[2],
xmax = offset[1] + 10.51 * res[1],
ymax = offset[2] + 2.49 * res[2]), crs = st_crs(l7))
l7[bb]
plot(l7[,1:13,1:13,1], reset = FALSE)
image(l7[bb,,,1], add = TRUE, col = sf.colors())
plot(st_as_sfc(bb), add = TRUE, border = 'green', lwd = 2)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.